Technical Abstract:
Losses from postharvest fruit decays range from 5% to more than 20% in the United States, depending on the commodity, and up to 50% in developing countries. Fungicides have been the main tool used to control fruit decay for more than three decades, but their use has become increasingly curtailed due to the perceived harmful effects on human health and the environment, declining effectiveness due to the development of resistance in major postharvest pathogens, and increasing difficulties in finding and registering new effective fungicides. Many postharvest pathogens, including Penicillum spp. and Botrytis spp., are necrotrophs that invade fruit through wounds which makes them particularly vulnerable to biocontrol by pre-emptive colonization. Resident fruit microorganisms have been the richest source of biocontrol agents against postharvest decay fungi. The general criteria considered during the initial selection of an antagonist include efficacy under storage conditions, spectrum of activity, growth rate on fruit tissue, compatibility with postharvest treatments and additives, potential for pathogenicity to plants, and its effect on human health, which may prevent the antagonist from being registered. Control of fruit decay can be enhanced by creating a physical and chemical environment favorable to the antagonists, physiological and genetic manipulation of the antagonist strains, developing antagonist mixtures, and integrating biocontrol with other alternative control methods. Developing a partnership with the private sector is essential for the commercialization of biocontrol agents. The commercial success of BioSaveTM, used against various postharvest decays of fruit and vegetables, can be attributed to its consistent decay control; conducting pilot tests in commercial packinghouses, which gained confidence of the fruit industry in the product; educating growers about the product and, according to EcoScience Corp., the manufacturer of the product, rigorous quality control; and extensive technical support. Current successes and rapid expansion and progress in postharvet biocontrol research worldwide suggests that we can expect greater use of biocontrol of postharvest decays in the future.